A student wanted to investigate the movement of water into and out of the plant cells. the student had the equipment shown in figure 11. the test tubes in the rack contain different concentrations of sodium chloride

the solutions were 0.1m, 0.2m, 0.3m, 0.4m and 0.5m sodium chloride solution

the test tubes in the beaker contain distilled water and there are three potato chips in each of the six test tubes

i) state why the test tube in the beaker only contains distilled water and three potato chips

ii) state two variables that need to be controlled in this investigation

iii) explain why the chips in the 0.5 sodium chloride lost mass